Reinsurance - Summary of the composition of pool of assets (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2023		Jun. 30, 2022	Dec. 31, 2022		Jan. 01, 2021
Effects of Reinsurance [Line Items]
Bonds available for sale	[1]	$ 222,530			$ 226,156
Fixed maturity securities - fair value option	[1]	4,941			4,485
Loans		52,411			50,321
Investment real estate		2,218			2,153
Short-term investments	[1]	10,955			12,376
Derivative assets net, carrying value		410			514
Derivative assets, net, fair value		5,216			6,049
Other assets		12,832	[1]		12,384	[1]	$ 13,520
Total assets		537,138			522,228		$ 598,841
Carrying Value
Effects of Reinsurance [Line Items]
Short-term investments		6,677			6,668
Other assets		37			33
Hedge Funds and Private Equity Funds
Effects of Reinsurance [Line Items]
Fair Value Using NAV Per Share (or its equivalent)		11,792			11,809
Commercial mortgage loans
Effects of Reinsurance [Line Items]
Loans		37,926			37,128
Policy loans
Effects of Reinsurance [Line Items]
Loans		1,762			1,758
Fortitude Holdings
Effects of Reinsurance [Line Items]
Change in net unrealized gains (losses), gross		376		$ (6,100)
Change in net unrealized gains (losses), net of tax		297		$ (4,800)
Derivative asset, Fair value of collateral		191			192
Derivative liability, Fair value of collateral		25			28
Fortitude Holdings | Carrying Value
Effects of Reinsurance [Line Items]
Bonds available for sale		17,595			18,821
Fixed maturity securities - fair value option		4,558			4,182
Investment real estate		126			133
Short-term investments		255			75
Funds withheld investment assets		29,011			29,566
Derivative assets net, carrying value		58			90
Other assets		611			782
Total assets		29,680			30,438
Fortitude Holdings | Estimated Fair Value
Effects of Reinsurance [Line Items]
Bonds available for sale		17,595			18,821
Fixed maturity securities - fair value option		4,558			4,182
Investment real estate		302			348
Short-term investments		255			75
Funds withheld investment assets		28,919			29,511
Derivative assets, net, fair value		58			90
Other assets		611			782
Total(d)		29,588			30,383
Fortitude Holdings | Hedge Funds and Private Equity Funds | Carrying Value
Effects of Reinsurance [Line Items]
Fair Value Using NAV Per Share (or its equivalent)		1,940			1,893
Fortitude Holdings | Hedge Funds and Private Equity Funds | Estimated Fair Value
Effects of Reinsurance [Line Items]
Fair Value Using NAV Per Share (or its equivalent)		1,940			1,893
Fortitude Holdings | Commercial mortgage loans | Carrying Value
Effects of Reinsurance [Line Items]
Loans		4,196			4,107
Fortitude Holdings | Commercial mortgage loans | Estimated Fair Value
Effects of Reinsurance [Line Items]
Loans, fair value		3,928			3,837
Fortitude Holdings | Policy loans | Carrying Value
Effects of Reinsurance [Line Items]
Loans		341			355
Fortitude Holdings | Policy loans | Estimated Fair Value
Effects of Reinsurance [Line Items]
Loans, fair value		$ 341			$ 355

[1] See Note 10 for details of balances associated with variable interest entities.